Tobacco moistening method open cores

ABSTRACT

A body of tobacco is moistened by providing the body with at least one unsupported elongate cavity, placing the body in a chamber, evacuating the chamber and passing steam there-into until the tobacco has received a predetermined quantity of moisture.

United States Patent Neville et al.

[ Aug. 12, 1975 TOBACCO MOISTENING METHOD OPEN CORES Inventors: Richard Ernest Gartside Neville,

Salisbury; John Austin Garrett, Andover, both of England Assignee: AMF Incorporated, White Plains,

Filed: Feb. 1, 1974 Appl. N0.: 438,922

Foreign Application Priority Data Feb. 8, 1973 United Kingdom 6357/73 US. Cl. 131/136 Int. Cl. A248 l/02 Field of Search... 131/133 A, 134, 135, 133 R, 131/140 R, 140 A, 136

[56] References Cited UNITED STATES PATENTS 2,827,058 3/1958 Bogaty 131/108 3,262,458 7/1966 Lindstroma... 131/133 R 3,372,703 3/1968 Conrad 131/133 R Primary Examiner-Robert W. Michell Assistant ExaminerV. Millin Attorney, Agent, or Firm-George W. Price; Charles .1. Worth [5 7 ABSTRACT A body of tobacco is moistened by providing the body with at least one unsupported elongate cavity, placing the body in a chamber, evacuating the'chamber and passing steam there-into until the tobacco has received a predetermined quantity of moisture.

6 Claims, 2 Drawing Figures PATENTED AUG 1 2 I975 SHEET PATENTEQ AUG i 2 97s SHEET TOBACCO MOISTENING METHOD OPEN CORES This invention relates to a process for the conditioning of tobacco.

Prior to the manufacture of cigarettes, it is necessary to treat the tobacco by moistening to prevent breakage of the leaf.

A tobacco conditioning process commonly used, is a vacuum process in which the leaf tobacco is placed in a chamber, the chamber evacuated and thereafter, steam admitted. The disadvantage with such a process is that not all the tobacco becomes conditioned. It has been found in practice that cold spots remain at the centre of the body of tobacco and the greater the density of tobacco, the less the tobacco becomes conditioned at the centre. In order to reduce these cold spots, the steam is recycled, but where the tobacco .is very dense, say over lb per cu.ft., it is often found that conditioning at the centre cannot be achieved.

In order to overcome the above disadvantage, processes are also known in which probes are used to draw air and steam through tobacco. However, it is found that the resistance to the flow of steam within a body of tobacco is greatest at the juncture of the probe and the tobacco contacting it. This resistance is aggravated by perforations in the probe. Also, the perforations can become blocked by scraps of tobacco and by compression of the tobacco by the probe in the vicinity thereof, further increasing resistance. The present invention avoids the disadvantages of the above processes.

According to the invention there is provided a process for moistening a body of tobacco comprising the steps of placing the body of tobacco having at least one elongate cavity formed therein within an enclosed chamber, evacuating the chamber, thereafter introducing steam into the chamber, and allowing the steam to pass in to the tobacco, said tobacco being unsupported at the elongate surface of said cavity, until the tobacco has received predetermined quantity of moisture.

Preferably the or each cavity in the body of tobacco is formed by coring the body prior to placing it within the chamber.

The vacuum is applied to the chamber prior to the introduction of steam into the chamber to draw steam through the body of tobacco.

Generally the method comprises forming the cavity in the body of tobacco by removing a core, evacuating a chamber in which the body of tobacco is positioned and then passing steam into the chamber, which steam passes through the body of tobacco via the cored hole, and the outer peripheral surface of the tobacco body. Preferably more than one cored hole is provided.

The core can be removed from the body of tobacco whilst inside or outside the chamber by means of an open ended and sharp edged corer tube pressed into the tobacco and then withdrawn with the core by means of a trepanning cutter or by inserting a core mould during packing, which is removed before processing.

Embodiments of the process according to the invention will now be described by way of example with reference to the apparatus shown in the accompanying drawing in which:

FIG. I is a schematic section showing an enclosed chamber in which a vacuum is applied.

FIG. 2 shows an arrangement by which conditioning is carried out semi-continuously on a conveyor belt.

, In the arrangement of FIG. 1 the body of tobacco 20 having a cored hole 22 rests on a flat trolley 21, having no aperture therein placed in a chamber 23. The chamber 23is provided with a pipe 25 connectible with a vacuum pump (not shown) via a flexible pipe (also not shown). Steam enters the chamber through inlet pipe 28 and may leave via a closable ven't pipe 29.

The chamber 23, which may be in bell form, can be lifted for loading and unloading. Alternatively, the chamber may be provided with doors through which the loaded trolleycan pass. The trolley 21 is run on a track (not shown) and can be moved from a coring station (not shown) where a coring head decends to effect a single or multiple coring of the tobacco. The coring station may form part of the chamber so that coring can take place with the tobacco in the chamber. 7

FIG. 2 shows a modification of the arrangement shown in FIG. 1. where the trolley and track are replaced by a perforated conveyor belt 36 running on pulleys 38, 39 and over a plate 40, the belt with or without chains extending from a coring station 41 to a processing station 42 where a bell shaped chamber 43 can be lowered over the belt, in sealing engagement therewith at seals 44, by a motor 45 supported on a framework F. The plate 40 is provided with an aperture 46 (or apertures), communicating with vacuum equipment 48 via a pipe 49. Steam is fed to the chamber 43 by an inlet pipe 50 and an aperture 51 and may leave by a closable vent pipe 52.

In the arrangement shown in FIG. 2, the steam may alternatively be fed in or the vacuum applied by flexible hose (not shown) connected to the bell shapepd chamber 43.

The coring station 41 comprises a multiple coring head 53 arranged on the framework F to be hydraulically mechanically, or pneumatically driven in a vertical direction. The head carries open ended and sharp edged corer tubes (one shown at 54).

Referring to FIG. 2 a typical bale of tobacco weighing 448 lbs having a density of 20-25 lb/cu.ft. can be conditioned by means of the apparatus described above in the following manner:

The tobacco is first cored vertically through the bale and then placed on the trolley or conveyor belt. After transporting the tobacco into the chamber, the latter is closed by airtight doors (not shown) or by engagement with the seals 44, and a vacuum applied. After about 4-8 minutes when the pressure is down to about 0.2 inches of mercury absolute, the chamber is isolated from the vacuum pump and steam is fed through inlet 50 into the chamber 43 until the pressure rises to between 6 and 12 inches of mercury absolute depending on the temperature and the amount of condensation required on the tobacco. This takes from 2-2 minutes, the pressure is then held for about one minute before the steam is shut off and the chamber vented.

Although FIG. 2 has been described with reference to a conveyor belt, the arrangement may alternatively be used with a truck on which trolleys loaded with the bales of tobacco are able to move into the chamber.

Furthermore, the trolley comprises a flat plate on wheels which engage with the track. The plate may be perforated to assist in the moistening action as described.

The above described cycle of operation may be repeated several times in order to effect sufficient conditioning of the tobacco, particularly where high density cases are being processed. To prevent the need for recycling, several cored holes can be provided.

An advantage of the elongate hole is that resistance to the flow of steam is considerably reduced compared with the resistance caused by the probe as mentioned above, in which case the process time can possibly be reduced.

A further advantage is that a larger hole can be prob. evacuating the chamber;

c. thereafter introducing steam into the chamber; and

d. allowing the steam to pass into the tobacco, said tobacco being unsupported at the elongate surface of said cavity, until the tobacco has received a predetermined quantity of moisture.

2. The process of claim 1 wherein the at least one cavity in the body of tobacco is formed by coring the body prior to placing the body in the chamber.

3. The process of claim 1, wherein the core is removed from the body by means of a sharp edged corer tube or a trepanning cutter.

4. The process of claim 1, wherein a plurality of said cavities are formed in the body in the form of cored holes.

5. The process of claim 1, wherein the tobacco is supported on a wheeled trolley within the chamber.

6. The process of claim 1, wherein the tobacco is supported on a travelling conveyor. 

1. A process for moistening a body of tobacco, comprising the steps of: a. placing the body of tobacco having at least one elongate cavity formed therein by cutting and removing the core, within an enclosed chamber; b. evacuating the chamber; c. thereafter introducing steam into the chamber; and d. allowing the steam to pass into the tobacco, said tobacco being unsupported at the elongate surface of said cavity, until the tobacco has received a predetermined quantity of moisture.
 2. The process of claim 1 wherein the at least one cavity in the body of tobacco is formed by coring the body prior to placing the body in the chamber.
 3. The process of claim 1, wherein the core is removed from the body by means of a sharp edged corer tube or a trepanning cutter.
 4. The process of claim 1, wherein a plurality of said cavities are formed in the body in the form of cored holes.
 5. The process of claim 1, wherein the tobacco is supported on a wheeled trolley within the chamber.
 6. The process of claim 1, wherein the tobacco is supported on a travelling conveyor. 